import re
s=input()
s=re.sub(r'S','0',s)
s=re.sub(r'ing','1',s)
s=re.sub(r'[a-zA-Z]','',s)
l=list(map(int,list(s)))
c=0
while len(l)>0:
	if l[0]<1: c+=sum(l)
	l=l[1:]
print(c)